Viper Defense presents our new Gen 2 AR 15 80% Lower Receiver which is machined from 6061-T6 Aircraft Grade Aluminum. Every machining process for the Billet 80% Lower is completed LESS the Trigger Pocket, Pin Holes and Safety Hole. It is Ready to be Machined into a Finished Lower Receiver.
We originally started our Billet Lower Receiver design as a straight-forward clone of an OEM Forging with an integral trigger guard. But then we realized that as a custom firearms manufacturer, we wanted to allow plenty of options for our customers plus flexibility in our products. First, after some thorough research, we discovered that a large number of aftermarket trigger guard designs are currently available, and we will want to add our versions to the mix in the future as well. We decided that with so many trigger guard options available, plus an integral trigger option, would provide plenty of flexibility for all of our customers.
But we didn't stop there. We designed our proprietary Gen2 Billet Upper Receiver to have an octagonal body shape, so we have a Lower Receiver with an octagonal stock mount to match that. But we also allowed for this Round Stock Mount shape to mate with any standard OEM Forged Upper Receiver.
One of the toughest aspects in manufacturing AR 15 Lower Receivers is machining the magazine well. Machining it from the top or bottom proves to be extremely difficult and may not produce a good enough finish, and then you have to broach the corners as well to allow common magazines to slide in and out. One ideal way to machine the magazine well is to use a process called Wire EDM, which provides great accuracy and tiny corner radii, but it's slow and expensive and some dislike the surface finish as well.
So what we did for our Gen2 Billet 80% Lower Receivers was to build up the front wall under the Pivot Pin and pull off the left hand side of the magazine well. In this manner, we can machine the well very accurately with small corner radii, and have a great finished surface for magazines to slide against, plus, it's pretty fast to manufacturer now.
6061 vs 7075 Aluminum
To us, six of one, half a dozen of another. If you look on the various gun forums on the internet, you'll see many people claiming to be the 'best qualified' to decide the question. We figure that our customers are the best qualified to decide what they want, so we made the material an option. The only true difference for us as manufacturer is the cost of the material, which 7075 is a bit more expensive due to being way less common. The machining charateristics appear to be the same between 6061 and 7075 since both are Aluminum and are being machined (like butter) with HSS drills and mills.
We're not sure what drives customer requests for their 80% Lower be Anodized, but we've added the option just the same. When you finish machining the Lower, you break the seal of the Anodizing that was done prior to your work. You have to do one of two things then - strip it completely and reseal the whole thing again, or just let it go. We're thinking at this time that most customers just let it go as long as it still looks finished from the outside when assembled, which it does.
Although not generally restricted, you should refer questions regarding manufacture, NFA Regulations, and individual state regulations to the ATF or obtain legal guidance prior to manufacturing.